1. Field of the Invention
The present invention relates to rotary control knobs generally and, more particularly, but not by way of limitation, to a novel, compact, low-cost, rotary control knob and indicator.
2. Background Art
Rotary control knobs are used in a variety of applications. While the present invention is described, for illustrative purposes only, as being applied to rotary control knobs in a vehicle, it will be understood that rotary control knobs of the present invention may be applied to any use in which it is desired to graphically represent the setting of a rotary control knob.
In vehicle applications, rotary knobs are employed, for example, to control environmental air flow and temperature in the vehicle operator/passenger compartment. Typically, such a control knob has a pointer that indicates the setting of the control knob by pointing to a control setting represented graphically on an arcuate scale circumjacent the knob. The pointer and the scale are illuminated by backlighting at night when the lights of the vehicle are turned on. Such a conventional control knob is typically injection molded of thermoplastic materials and is relatively expensive to manufacture, since it requires the use of either a multistep molding process or the injection of two or more separate different colored or clear materials in a single mold.
A single-material control knob can be fabricated in which the pointer is not backlighted, but, rather, the pointer extends from the periphery of the control knob and covers a desired setting on the graphical scale. With this arrangement, of course, one cannot view the setting that is covered. In some cases, the setting can be inferred from adjacent, non-covered settings, but, in other cases, it cannot.
With both of the above conventional rotary control knobs, the area required for the total layout comprises the area of the knob and the surrounding graphical representation. In some cases, this area consumed is less compact than is desirable.
Accordingly, it is a principal object of the present invention to provide a rotary control knob which is cast of a single material, but which can be backlighted.
It is a further object of the invention to minimize the area that a rotary control knob and the accompanying graphical representation consume, preferably no more than the area of the knob itself.
It is an additional object of the invention to provide such a rotary control knob which can be economically manufactured using conventional techniques known in the art.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.